Rotary pump



p 1927' A. c. STEWART ROTARY PUMP Filed Aug- 6, 1923 Patented Sept. 6,, 1927.

C. STEWART, PASADENA, CALIFORNIA.

ROTARY PUMP.

Application am August e, 1923. SerlalNo. 656,138.

This invention relates to an apparatus for use in pumping va ors, gases, or liquids and the main object o the invention is to provide .a pump which will present the advantages in regard to simplicityv in construction and operation of a rotary pump while at the same time avoiding the difliculties of packing of the working piston which are usually present in rotary pumps.

Another object of the invention is to 'pro vide a pump which is especially adapted to be driven by motors such as single phase alternating current motors having small starting torque. the pump being of such construction and operation that effective load or resistance is not developed thereby until a considerable speed is obtained. Other objects of the invention will appear hereinafter.

The accompanyin drawing illustrates an embodiment of my invention and referring hereto:

Fig. 1 is a transverse section of the pump. Fig. 2 is a longitudinal section thereof. Fig. 3 is a partial plan view of the shaft for the pump,.showing the valve ports therein v The pump shown in the drawing is mounted on a base'or frame 1 carrying a standard 2 which supports a stationary shaft 3 on which the pump members are mounted to rotate, the said shaft being held in stationary or nonrotative position by any suitable means. I prefer to provide the shaft 3 with longitudinal bores or assages 4 and 5 through which the :fiui to be pumped is supplied to and. delivered from the pump as hereinafter described. A rotary member or carrier 6 is mounted to rotate on the stationmy shaft 3 and is provided with any suitable driving means, for example, a pulley 7 mounted or formed thereon, said rotary carrier being also provided or formed with any desired number of cylinders 8 extending radially with respect to the axis of rotation of said rotary carrier. In the drawing two of said cylinders are shownbut it will be understood that any desired number may be used, it being preferred however in any case W to so position the cylinders as to balance the weight thereon around the axis of rotation as far as possible Each cylinder 8 is provided with an inlet port 9 adapted to register with an inlet port 10 in the wall of the shaft,

hollow shaft 3 and connecting with the inle passage 4 effected during a portion only of the rotation of the rotary carrier. Each cylinder is further provided with an outlet port 11 adapted to register during a portion of the rotation of the carrier with an outlet port v12 in the wall of the hollow shaft 3 communicating with the outlet passage 5 in said The aforesaid inlet and outlet orts are so positioned that the times of reglstration of the inlet passage for take place at periods between the times of registration of the outlet ports for said cylinder, so that each cylinder is connected alternately to the inlet passage and to the outlet passage. A piston 13 is mounted to slide in each of the cylinders 8, such piston being provided if necessary with packing rings or other means for maintaining sufficiently tight engagement thereof with the walls of the cylinder to prevent any substantial leakage of fluid between such parts. Each piston is further provided with a thrust pin or member 14 which is fitted loosely in a recess or socket 15 in the piston and is adapted to engage at its outer, end with a cylindrical eccentric face 16 on a rotary controlling or eccentric member 17 which is mounted to turn on the standard Q around an axis of rotation which is concentric with cylindrical cam face 16, but is ec-' any cylinderaforesaid, such'regiistration being centric to the axis of rotation of the rotary member 6. The recess 15 ,is of suflicient width to allow a slight tilting movement of the thrust member 14: and the inner end of said thrust member is preferably) rounded or tapered to fit the corresponding rounded or tapered inner end of said socket or recess to provide for such tilting movement. The rotary eccentric member 17 rotates freely upon a bearing means 18 shown as a bearing mounted on the stationary shaft 3, but with its axis displaced from the axis of said shaft by a distance equal to one half of the required piston stroke. As shown m Fig. 2, the eccentric controlling member 17 is preferably mounted beside the rotary carrier member 6 at the opposite side from the driving means or pulley 7 and encloses said carrier member only at such side and at its peripheral surface. By such a construction the device may be conveniently dismantled and assembled, as the rotary carrier member,

ball

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me mbsr eniy at such (apposite side and at the peripheral surface thereof so'as to permit said carrier membew, together with tbs pistons and thrust members 130 be freely moved axially ints and out of position to ba so e11 closed, andsald contmflmg msmbsr bemg" provided with $1 cylindrical facseccentric to said shaft and sdapiecl to sngags said thrust members to force the respective pistons i'n- ALFRED G. STEWART, 

